1DEV

CRYSTAL STRUCTURE OF SMAD2 MH2 DOMAIN BOUND TO THE SMAD-BINDING DOMAIN OF SARA

• PDB DOI:  https://doi.org/10.2210/pdb1DEV/pdb

• Classification: SIGNALING PROTEIN
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 1999-11-15 Released: 2000-01-21 
• Deposition Author(s): Shi, Y., Wu, G.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.20 Å
• R-Value Free: 0.276 
• R-Value Work: 0.218 
• R-Value Observed: 0.220 

Literature

Structural basis of Smad2 recognition by the Smad anchor for receptor activation.

Wu, G., Chen, Y.G., Ozdamar, B., Gyuricza, C.A., Chong, P.A., Wrana, J.L., Massague, J., Shi, Y.

(2000) Science 287: 92-97

• PubMed: 10615055 
• DOI: https://doi.org/10.1126/science.287.5450.92
• Primary Citation of Related Structures:  
  1DEV


• PubMed Abstract: 
  

The Smad proteins mediate transforming growth factor-beta (TGFbeta) signaling from the transmembrane serine-threonine receptor kinases to the nucleus. The Smad anchor for receptor activation (SARA) recruits Smad2 to the TGFbeta receptors for phosphorylation. The crystal structure of a Smad2 MH2 domain in complex with the Smad-binding domain (SBD) of SARA has been determined at 2.2 angstrom resolution. SARA SBD, in an extended conformation comprising a rigid coil, an alpha helix, and a beta strand, interacts with the beta sheet and the three-helix bundle of Smad2. Recognition between the SARA rigid coil and the Smad2 beta sheet is essential for specificity, whereas interactions between the SARA beta strand and the Smad2 three-helix bundle contribute significantly to binding affinity. Comparison of the structures between Smad2 and a comediator Smad suggests a model for how receptor-regulated Smads are recognized by the type I receptors.

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Organizational Affiliation: 

Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Princeton, NJ 08544, USA.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

Biological assembly 1 assigned by authors and generated by PISA (software)

Biological Assembly 2  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

Biological assembly 2 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 52.82 kDa 
• Atom Count: 3,643 
• Modelled Residue Count: 466 
• Deposited Residue Count: 474 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
MAD (mothers against decapentaplegic, Drosophila) homolog 2	A, C	196	Homo sapiens	Mutation(s): 0  Gene Names: SMAD2, MADH2, MADR2
UniProt & NIH Common Fund Data Resources
Find proteins for Q15796 (Homo sapiens) Explore Q15796  Go to UniProtKB:  Q15796
PHAROS:  Q15796

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Smad anchor for receptor activation	B, D	41	Homo sapiens	Mutation(s): 0  Gene Names: ZFYVE9, MADHIP, SARA, SMADIP
UniProt & NIH Common Fund Data Resources
Find proteins for O95405 (Homo sapiens) Explore O95405  Go to UniProtKB:  O95405
PHAROS:  O95405

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.20 Å
• R-Value Free: 0.276 
• R-Value Work: 0.218 
• R-Value Observed: 0.220 
• Space Group: P 3₁ 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 138.5	α = 90
b = 138.5	β = 90
c = 55.9	γ = 120

Software Package:

Software Name	Purpose
AMoRE	phasing
X-PLOR	refinement
DENZO	data reduction
SCALEPACK	data scaling

Structure Validation

Entry History 

Deposition Data

• Released Date: 2000-01-21 
Deposition Author(s): Shi, Y., Wu, G.

Revision History  

• Version 1.0: 2000-01-21
  Type: Initial release
  
• Version 1.1: 2008-04-27
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2018-01-31
  Changes: Experimental preparation